The present invention relates to a wheel suspension system and, more particularly, to a wheel suspension system for controlling the lateral displacement of a wheel in response to vertical movement of the wheel.
Suspension systems support and cushion the ride of a vehicle. One type of conventional wheel suspension system involves a wishbone design, as generally shown in FIGS. 1, 2A, and 2B. The traditional wishbone suspension system includes an upper wishbone and lower wishbone connected to a wheel support on one end and a vehicle chassis on the other end. Typically, the upper and lower wishbones are spaced above and below the center line of the wheel support as defined by the axle of the wheel.
Numerous drawbacks are encountered by conventional wishbone designs. Ordinarily, the conventional wheel support is displaced vertically in response to various surface conditions encountered by the tire of the vehicle. Indeed, if the wishbones are not pointed directly away from the center line of the vehicle, the wheel ordinarily will move closer to the center line of the vehicle in response to vertical displacement of the wheel, as shown in FIG. 2B. The periodic lateral displacement of the wheel resulting from variations in road surfaces typically will result in increased wear on the tire, lessened roadholding performance, and reduced gas mileage.
Related art includes systems that have been designed to provide more uniform contact of the tire to the road during movements of the wheel and systems designed to reduce roll center movement and camber changes.
U.S. Pat. No. 5,114,176 discloses a suspension system for a steered wheel in which the contact between the wheel and ground is maintained substantially uniform during all movements of the wheel. The suspension system includes an axle carrier having a bifurcated upper portion consisting of inwardly extending arms that are pivotally connected through a pin-type joint to a pair of inwardly facing arm sections of a Y-shaped upper arm. Additionally, a generally Y-shaped lower arm is pivotally supported along a pair of brackets affixed to the body.
U.S. Pat. No. 5,286,052 discloses a double wishbone suspension system for a motor vehicle. The suspension system includes a lower transversely extending control arm and an upper control arm, which are pivotally connected to lower and upper wheel carriers, respectively. This patent is directed to achieving reduced roll center movement and enables wheel camber changes relative to the vehicle body during vertical movement of the suspension travel, as the wheel responds to changing road conditions. While various suspension systems have attempted to overcome various problems with standard suspension systems, none have allowed the successful control of horizontal displacement of the wheel relative to the center line of the chassis of the vehicle.